# Universal events
Universal events are required for all RTMS implementations. They handle the connection handshake protocol, keep-alive operations, session and stream state management, and media data delivery.
> Use these events with the product-specific events for your implementation. For Meetings, Webinars, or Video SDK, see [Session events](/docs/rtms/event-reference/session-events/). For Contact Center, see [Contact Center events](/docs/rtms/event-reference/contact-center-events/).
## Message transmission channels
RTMS events are transmitted through two connection types established during the handshake process.
| Signaling connection | Media connection |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- |
| `SIGNALING_HAND_SHAKE_REQ``SIGNALING_HAND_SHAKE_RESP``DATA_HAND_SHAKE_REQ``DATA_HAND_SHAKE_RESP``EVENT_SUBSCRIPTION``EVENT_UPDATE``CLIENT_READY_ACK``STREAM_STATE_UPDATE``SESSION_STATE_UPDATE``SESSION_STATE_REQ``SESSION_STATE_RESP``KEEP_ALIVE_REQ``KEEP_ALIVE_RESP``STREAM_STATE_REQ``STREAM_STATE_RESP``STREAM_CLOSE_REQ``STREAM_CLOSE_RESP``VIDEO_SUBSCRIPTION_REQ``VIDEO_SUBSCRIPTION_RESP` | `KEEP_ALIVE_RESP``MEDIA_DATA_AUDIO``MEDIA_DATA_VIDEO``MEDIA_DATA_SHARE``MEDIA_DATA_TRANSCRIPT``MEDIA_DATA_CHAT` |
> The examples on this page use meeting-specific values (such as `meeting_uuid` and `meeting.rtms_started`), but the message structure is the same across all RTMS-supported products.
## Signaling handshake request
Sent to the signaling connection
Send a signed handshake request to the `server_urls` provided in the `meeting.rtms_started` event, also known as the signaling connection. Use your app credentials with the session details to generate the signature. For more information, see [App establishes signaling connection](/docs/rtms/event-reference/).
> Use `meeting.rtms_started` and `meeting.rtms_stopped` events in the [Webhook reference](/docs/api/rtms/events) to get initial session details like the `meeting_uuid` and `rtms_stream_id`.
```json
{
"msg_type": 1,
"protocol_version": 1,
"sequence": 1,
"meeting_uuid": "xxxxxxxxxx",
"rtms_stream_id": "xxxxxxxxxx",
"signature": "xxxxxxxxxx",
"buffer_data": false
}
```
| Field | Type | Description |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The request from the app to the RTMS server to initiate a handshake. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `protocol_version` | int | The RTMS design version. By default, it's `1.0`. |
| `sequence` | int | The sequence number of the message. Must start at `1`. |
| `meeting_uuid` | string | The unique identifier for the session. |
| `rtms_stream_id` | string | The unique identifier of the RTMS stream. Multiple streams are possible for a session if streaming access stops or restarts. |
| `signature` | string | The authentication signature created using app credentials and session details. |
| `buffer_data` | bool | Optional. Default is `true`. When set to `false`, any audio data captured between the time the `rtms_started` webhook event is received and the time the signaling connection is established will be dropped. |
| > When `buffer_data` is set to `false`, only the initial buffer data is dropped. Audio data will continue to be buffered during connection interruptions, and any buffered data will be transmitted once a new connection is established. |
## Signaling handshake response
Sent from the signaling connection
The signaling connection will respond with a signaling handshake response that includes the URLs of the media connections.
```json
{
"msg_type": 2,
"protocol_version": 1,
"sequence": 0,
"status_code": 0,
"reason": "",
"media_server": {
"server_urls": {
"audio": "wss://127.0.0.0:443",
"video": "wss://127.0.0.0:443",
"transcript": "wss://127.0.0.0:443",
"all": "wss://127.0.0.0:443"
}
}
}
```
| Field | Type | Description |
| ------------------ | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The response from the signaling connection to the app after a handshake attempt. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `protocol_version` | int | The RTMS design version. By default, it's `1.0`. |
| `sequence` | int | The sequence number of the message. |
| `status_code` | int | The status code of the message. Status `0` means success. For more information, see [RTMS_STATUS_CODE](/docs/rtms/data-types/#rtms_status_code). |
| `reason` | string | This is empty if successful. If failed, it will contain the reason for the failure. |
| `media_server` | object | The media connection information. |
| `server_urls` | object | Locations of available media connections. The response will depend on the app's available scopes. For example, if the app only supports audio, only `audio` will be included. |
## Media handshake request
Sent to the media connection
To establish a connection, send a handshake request to the media connections of the RTMS server(s) that were included in the signaling handshake and include the associated media parameters. The media connection responds with confirmed parameters of the requested media types.
Apps can request all available media streams or specify media streams by content type. If all are requested, the signaling connection responds with all media connections available according to the app's requested scopes.
If the app has scopes for audio and transcript only, a request for all media will include audio and transcript data but not video, chat, or screen share data.
To request only one media type, specify that media type in the `media_type` field. For more information, see [MEDIA_DATA_TYPE](/docs/rtms/data-types/#media_data_type). Use `"media_type": 32` for all.
Media parameters (`media_params`) are optional. If not specified, the default values will be used.
> For more information, see [Data type definitions](/docs/rtms/data-types) for options on codecs, resolutions, rates, etc.
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4xxxxxxxxxx",
"rtms_stream_id": "xxxxxxxxxx",
"signature": "xxxxxxxxxx",
"media_type": 32,
"media_params": {
"audio": {
"content_type": 2,
"sample_rate": 1,
"channel": 1,
"codec": 1,
"data_opt": 1,
"send_rate": 100
},
"video": {
"codec": 5,
"resolution": 2,
"fps": 5
},
"deskshare": {
"codec": 5,
"resolution": 3,
"fps": 1
},
"transcript": {
"content_type": 5,
"src_language": 9,
"enable_lid": true
}
}
}
```
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4nYtdqLVTVqGJ+QB62ED7Q==",
"rtms_stream_id": "03db704592624398931a588dd78200cb",
"signature": "kDBZVzEWgox9tWVBc7DHsjW2OnVD/6H1zN2vdmU9VY8=",
"media_type": 1,
"media_params": {
"audio": {
"content_type": 2,
"sample_rate": 1,
"channel": 1,
"codec": 1,
"data_opt": 1,
"send_rate": 20
}
}
}
```
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4nYtdqLVTVqGJ+QB62ED7Q==",
"rtms_stream_id": "03db704592624398931a588dd78200cb",
"signature": "kDBZVzEWgox9tWVBc7DHsjW2OnVD/6H1zN2vdmU9VY8=",
"media_type": 2,
"media_params": {
"video": {
"codec": 5,
"resolution": 2,
"fps": 5
}
}
}
```
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4nYtdqLVTVqGJ+QB62ED7Q==",
"rtms_stream_id": "03db704592624398931a588dd78200cb",
"signature": "kDBZVzEWgox9tWVBc7DHsjW2OnVD/6H1zN2vdmU9VY8=",
"media_type": 4,
"media_params": {
"deskshare": {
"codec": 5,
"resolution": 3,
"fps": 1
}
}
}
```
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4nYtdqLVTVqGJ+QB62ED7Q==",
"rtms_stream_id": "03db704592624398931a588dd78200cb",
"signature": "kDBZVzEWgox9tWVBc7DHsjW2OnVD/6H1zN2vdmU9VY8=",
"media_type": 8,
"media_params": {
"transcript": {
"content_type": 5,
"src_language": 9,
"enable_lid": true
}
}
}
```
```json
{
"msg_type": 3,
"protocol_version": 1,
"sequence": 0,
"meeting_uuid": "4nYtdqLVTVqGJ+QB62ED7Q==",
"rtms_stream_id": "03db704592624398931a588dd78200cb",
"signature": "kDBZVzEWgox9tWVBc7DHsjW2OnVD/6H1zN2vdmU9VY8=",
"media_type": 16
}
```
| Field | Type | Description |
| -------------------------------------------------------------------------------------------------- | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The app sends this message to the media connection to request a connection with the specified media parameters. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `protocol_version` | int | The RTMS design version. By default, it's `1.0`. |
| `sequence` | int | The sequence number of the message. |
| `meeting_uuid` | string | The unique identifier for the session. |
| `rtms_stream_id` | string | The unique identifier of the RTMS stream. Multiple streams are possible for a session if streaming access stops or restarts. |
| `signature` | string | The authentication signature created using app credentials and session details. |
| `media_type` | int | The media type of the stream, either audio (1), video (2), screen share (4), transcript (8), chat (16), or all (32). For more information, see [MEDIA_DATA_TYPE](/docs/rtms/data-types/#media_data_type). |
| `media_params` (Optional) | object | The media parameters of the stream that define the media formats. Parameters are set to default if not specified and returned in the response. |
| `content_type` | int | The content type of the media stream, either RTP (1), raw audio (2), raw video (3), file stream (4), or text (5). For more information, see [MEDIA_CONTENT_TYPE](/docs/rtms/data-types/#media_content_type). |
| `sample_rate` (audio) | int | The sample rate of the audio stream. For more information, see [AUDIO_SAMPLE_RATE](/docs/rtms/data-types/#audio_sample_rate). |
| `channel` (audio) | int | The channel of the audio stream, either mono (1) or stereo (2). For more information, see [AUDIO_CHANNEL](/docs/rtms/data-types/#audio_channel). |
| `codec` (audio) | int | The codec of the audio data. Can be L16 (1), G711 (2), G722 (3), or Opus (4). For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `data_opt` (audio) | int | Defines whether media is separated or merged. For example, mixed audio or separated audio streams. For more information, see [MEDIA_DATA_OPTION](/docs/rtms/data-types/#media_data_option). |
| `send_rate` (audio) | int | The send rate of the audio stream in milliseconds (ms). Must be a multiple of 20, up to 1000 ms. |
| `codec` (video) | int | The codec of the video data that is set during the handshake and doesn't change during the session. Can be JPG or PNG when `fps` {'<='} 5 and H.264 when `fps` > 5. The default is JPG with an `fps` of 5.If the handshake request sets the `fps` > 5 but doesn't specify a `codec`, the server will set the `codec` to JPG (default) and the `fps` to 5. For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `codec` (screen share) | int | The codec of the screen share data that is set during the handshake and doesn't change during the session. Can be JPG or PNG when `fps` {'<='} 1 and H.264 when `fps` > 1. The default is JPG with an `fps` of 1.If the handshake request sets the `fps` > 1 but doesn't specify a `codec`, the server will set the `codec` to JPG (default) and the `fps` to 1. For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `resolution` (video) | int | The resolution of the video stream. Can be SD (1), HD (2), FHD (3), or QHD (4). The default is HD. For more information, see [MEDIA_RESOLUTION](/docs/rtms/data-types/#media_resolution). |
| `resolution` (screen share) | int | The resolution of the screen share stream. Can be SD (1), HD (2), FHD (3), or QHD (4). The default is FHD. For more information, see [MEDIA_RESOLUTION](/docs/rtms/data-types/#media_resolution). |
| `fps` (video & screen share) | int | The frames per second of the video stream. Maximum of 30. |
| `src_language` | int | Optional. The language of the transcript. If not specified, English will be the default language for the first 30 seconds of transcription. If specified, RTMS will transcribe the first 30 seconds of audio based on this language setting. For more information, see [RTMS_TRANSCRIPT_LANGUAGE](/docs/rtms/data-types/#rtms_transcript_language). |
| > After 30 seconds, the audio language will be automatically detected and override this parameter. |
| `enable_lid` | bool | Optional. Default is true and Language Identification is enabled. When set to false, Language Identification is disabled and transcription will rely solely on the `src_language` parameter. |
## Media handshake response
Sent from the media connection
The media connection will respond with with a media handshake response that includes information about the media connections.
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"audio": {
"content_type": 2,
"sample_rate": 1,
"channel": 1,
"codec": 1,
"data_opt": 1,
"send_rate": 100
},
"video": {
"content_type": 3,
"codec": 5,
"resolution": 2,
"data_opt": 3,
"fps": 5
},
"deskshare": {
"content_type": 3,
"codec": 5,
"resolution": 3,
"fps": 1
},
"transcript": {
"content_type": 5,
"src_language": 9,
"enable_lid": true
},
"chat": {
"content_type": 5
}
}
}
```
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"audio": {
"content_type": 2,
"sample_rate": 1,
"channel": 1,
"codec": 1,
"data_opt": 1,
"send_rate": 100
}
}
}
```
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"video": {
"content_type": 3,
"codec": 5,
"resolution": 2,
"data_opt": 3,
"fps": 5
}
}
}
```
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"deskshare": {
"content_type": 3,
"codec": 5,
"resolution": 3,
"fps": 1
}
}
}
```
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"transcript": {
"content_type": 5,
"src_language": 9,
"enable_lid": true
}
}
}
```
```json
{
"msg_type": 4,
"protocol_version": 1,
"status_code": 0,
"reason": "",
"sequence": 0,
"payload_encrypted": true,
"media_params": {
"chat": {
"content_type": 5
}
}
}
```
| Field | Type | Description |
| -------------------------------------------------------------------------------------------------- | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The response from the media connection to the app after a handshake attempt. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `protocol_version` | int | The RTMS design version. By default, it's `1.0`. |
| `status_code` | int | The status code of the message. Status `0` means success. For more information, see [RTMS_STATUS_CODE](/docs/rtms/data-types/#rtms_status_code). |
| `reason` | string | This is empty if successful. If failed, it will contain the reason for the failure. |
| `sequence` | int | The sequence number of the message. |
| `payload_encryption` (Optional) | bool | Default is false for any TLS connection. The encryption keys in the signaling handshake response message. If true, the payload is encrypted. If false, but the payload protocol is UPD, and the payload will still be encrypted. |
| `content_type` | int | The content type of the media. For more information, see [MEDIA_CONTENT_TYPE](/docs/rtms/data-types/#media_content_type). |
| `sample_rate` | int | The sample rate of the audio stream. For more information, see [AUDIO_SAMPLE_RATE](/docs/rtms/data-types/#audio_sample_rate). |
| `channel` | int | The channel of the audio stream, either mono (1) or stereo (2). For more information, see [AUDIO_CHANNEL](/docs/rtms/data-types/#audio_channel). |
| `codec` | int | The codec of the audio data. Can be L16 (1), G711 (2), G722 (3), or Opus (4). For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `data_opt` | int | Defines whether media is separated or merged. For example, mixed audio or separated audio streams. For more information, see [MEDIA_DATA_OPTION](/docs/rtms/data-types/#media_data_option). |
| `send_rate` | int | The send rate of the audio stream in milliseconds (ms). Must be a multiple of 20. Can be up to 1000 ms. |
| `codec` (video) | int | The codec of the video data that is set during the handshake and doesn't change during the session. Can be JPG or PNG when `fps` {'<='} 5 and H.264 when `fps` > 5. The default is JPG with an `fps` of 5.If the handshake request sets the `fps` > 5 but doesn't specify a `codec`, the server will set the `codec` to JPG (default) and the `fps` to 5. For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `codec` (screen share) | int | The codec of the screen share data that is set during the handshake and doesn't change during the session. Can be JPG or PNG when `fps` {'<='} 1 and H.264 when `fps` > 1. The default is JPG with an `fps` of 1.If the handshake request sets the `fps` > 1 but doesn't specify a `codec`, the server will set the `codec` to JPG (default) and the `fps` to 1. For more information, see [MEDIA_PAYLOAD_TYPE](/docs/rtms/data-types/#media_payload_type). |
| `resolution` (video) | int | The resolution of the video stream. Can be SD (1), HD (2), FHD (3), or QHD (4). The default is HD. For more information, see [MEDIA_RESOLUTION](/docs/rtms/data-types/#media_resolution). |
| `resolution` (screen share) | int | The resolution of the screen share stream. Can be SD (1), HD (2), FHD (3), or QHD (4). The default is FHD. For more information, see [MEDIA_RESOLUTION](/docs/rtms/data-types/#media_resolution). |
| `fps` (video & screen share) | int | The frames per second of the video stream. Maximum of 30. |
| `src_language` | int | Optional. The language of the transcript. If not specified, English will be the default language for the first 30 seconds of transcription. If specified, RTMS will transcribe the first 30 seconds of audio based on this language setting. For more information, see [RTMS_TRANSCRIPT_LANGUAGE](/docs/rtms/data-types/#rtms_transcript_language). |
| > After 30 seconds, the audio language will be automatically detected and override this parameter. |
| `enable_lid` | bool | Optional. Default is true and Language Identification is enabled. When set to false, Language Identification is disabled and transcription will rely solely on the `src_language` parameter. |
## Client ready ACK message
Sent to the signaling connection
After the app receives the data handshake response from the media connection, it needs to send a client ready ack to the signaling connection to indicate that the full handshake has completed and that it is ready to receive media data.
This message should be sent after the signaling and media connections have been established.
```json
{
"msg_type": 7,
"rtms_stream_id": "xxxxxxxxxx"
}
```
| Field | Type | Description |
| ---------------- | --------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The app sends this message to the signaling connection to acknowledge that the server is ready to receive media. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_stream_id` | string | The unique identifier for the RTMS stream. |
## Keep-alive request
Sent from the media connection
To maintain stable connections and prevent timeouts, RTMS servers send a keep-alive request to both the signaling and media connections every 10 seconds.
When three keep-alive requests are unanswered, the RTMS server takes different actions for the different connection types.
- **Signaling connection** - The RTMS server will interrupt both the signaling and media connections, wait for one minute to allow for reconnection, and, if the connection is not restored, it will end the RTMS stream.
- **Media connections** - The RTMS server will interrupt the media connection, wait for 65 seconds to allow for reconnection, and, if the connection is not restored, it will end the RTMS stream.
If an app doesn't receive a keep-alive request for 65 seconds, we recommend that the app reestablish the connection by resending the [signaling handshake request](/docs/rtms/event-reference/#signaling-handshake-request). For more information, see
[Working with streams](/docs/rtms/event-reference/).
The RTMS server sends the following request to confirm the app wants to maintain a connection.
```json
{
"msg_type": 12,
"timestamp": 1727384349123
}
```
| Field | Type | Description |
| ----------- | --------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The media connection sends this message to confirm the app wants to maintain a connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `timestamp` | unsigned long | The Unix timestamp of the request. |
## Keep-alive response
Sent to the media connection
To maintain the connection, an app should respond to the request with the following response. The timestamp in the response must match the request.
```json
{
"msg_type": 13,
"timestamp": 1727384349123
}
```
| Field | Type | Description |
| ----------- | --------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The app sends this message to the media connection to maintain a connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `timestamp` | unsigned long | The Unix timestamp of the keep-alive request. |
## Subscribe to events
Sent to the signaling connection
Send this message to the signaling connection to get data about behavior during sessions.
> **Note**
>
> Some events are sent automatically and don't need to be subscribed to. To ensure your app works as expected, don't subscribe to these events.
>
> - FIRST_PACKET_TIMESTAMP = 1
> - MEDIA_CONNECTION_INTERRUPTED = 7
This message does not require a response.
```json
{
"msg_type": 5,
"events": [
{
"event_type": 2,
"subscribe": true
}
]
}
```
| Field | Type | Description |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The app sends this message to the signaling connection to subscribe or unsubscribe to in-session events from the signaling connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `event_type` | int | The type of event to subscribe to. For more information, see [RTMS_EVENT_TYPE](/docs/rtms/data-types/#rtms_event_type). |
| `subscribe` | bool | A boolean. `True` - subscribe to events `False` - unsubscribe from events |
## Audio data
Sent from the media connection
Audio data from the media connection of a participant in a session. It can be either merged audio or individual audio.
```json
{
"msg_type": 14,
"content": {
"user_id": 16778240,
"user_name": "John Smith",
"data": "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",
"length": 1024,
"timestamp": 1738392033699
}
}
```
```json
{
"msg_type": 14,
"content": {
"user_name": "John Smith",
"data": "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"
}
}
```
```json
{
"msg_type": 14,
"content": {
"channel_id": "c8b2d3ce-b0d6-4cd1-9195-fe17a4bd5b8e",
"data": "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",
"length": 1024,
"timestamp": 1738392033699
}
}
```
| Field | Type | Description |
| ------------ | --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | Audio data sent from the media connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | int | The unique identifier of the participant whose audio is included in the data. |
| `user_name` | string | The username of the participant whose audio is included in the data. If the `user_id` in the RTP header is `0`, no `user_name` will be sent. |
| `channel_id` | string | For Zoom Contact Center engagements, the unique identifier of the SIP trunk channel that carries this audio. Each party in an engagement is on a separate channel, so `channel_id` identifies which side of the call this audio belongs to. |
| `data` | string | Audio data, base64-encoded binary. |
| `length` | int | The length of the original binary data before base64 encoding. |
| `timestamp` | unsigned long | The Unix timestamp of the data. |
## Video data
Sent from the media connection
Video data from the media connection of the **Active speaker** participant in a session.
```json
{
"msg_type": 15,
"content": {
"user_id": 16778240,
"user_name": "John Smith",
"data": "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",
"length": 1024,
"timestamp": 1738392033699
}
}
```
| Field | Type | Description |
| ----------- | --------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | Video data sent from the media connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | int | The unique identifier of the participant whose video was included in the data. |
| `user_name` | string | The username of the participant whose video was included in the data. |
| `data` | string | Video data, base64-encoded binary. |
| `length` | int | The length of the original binary data before base64 encoding. |
| `timestamp` | unsigned long | The Unix timestamp of the data. |
## Screen share data
Sent from the media connection
Content shared by a participant in a session sent from the media connection.
```json
{
"msg_type": 16,
"content": {
"user_id": 16778240,
"user_name": "John Smith",
"data": "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",
"length": 1024,
"timestamp": 1738392033699
}
}
```
| Field | Type | Description |
| ----------- | --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| `msg_type` | int | Screen share data sent from the media connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | int | The unique identifier of the participant who shared their screen. |
| `user_name` | string | The username of the participant who shared their screen. |
| `data` | string | Screen share video data, base64-encoded binary. |
| `length` | int | The length of the original binary data before base64 encoding. |
| `timestamp` | unsigned long | The Unix timestamp of the data. |
## Transcript data
Sent from the media connection
Transcript of the spoken audio in a session sent from the media connection. Messages will be sent separately for each participant who has spoken.
```json
{
"msg_type": 17,
"content": {
"user_id": 19778240,
"user_name": "John Smith",
"start_time": 1727384100000,
"end_time": 1727384310000,
"timestamp": 1727384349000,
"language": 9,
"data": "Hi, hello world!"
}
}
```
```json
{
"msg_type": 17,
"content": {
"channel_id": "c8b2d3ce-b0d6-4cd1-9195-fe17a4bd5b8e",
"start_time": 1738392033699,
"end_time": 1738392036866,
"timestamp": 1727384349000000,
"language": 9,
"data": "Hi, hello world!"
}
}
```
| Field | Type | Description |
| ------------ | --------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | Transcript data sent from the media connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | int | The unique identifier of the participant whose transcript is included. |
| `user_name` | string | The username of the participant whose transcript is included. |
| `channel_id` | string | For Zoom Contact Center engagements, the unique identifier of the SIP trunk channel that carries this transcript. Each party in an engagement is on a separate channel, so `channel_id` identifies which side of the call this transcript belongs to. |
| `start_time` | unsigned long | The Unix timestamp of when the transcription started. |
| `end_time` | unsigned long | The Unix timestamp of when the transcription ended. |
| `timestamp` | unsigned long | The Unix timestamp of the data. |
| `language` | int | The language of the transcript data. For more information, see [RTMS_TRANSCRIPT_LANGUAGE](/docs/rtms/data-types/#rtms_transcript_language). |
| `data` | string | The transcript data, UTF-8 encoded string. |
## Chat data
Sent from the media connection
Chat data sent from the media connection. Each participant's chat data is sent in a separate message.
> **Note**
>
> RTMS currently delivers public, or everyone, meeting and webinar chat only (`chat_session.type: 1`). Other chat session types are reserved for future support and aren't delivered to clients today.
```json
{
"msg_type": 18,
"content": {
"timestamp": 1771635627032,
"data": "Content of the message",
"chat_session": {
"type": 1
},
"operation_type": 1,
"message_id": "1-{BAE4D8D3-629A-48E2-9C12-5442D81931BF}",
"sender": {
"user_id": 16778240,
"user_name": "John Smith"
},
"files": [
{
"file_id": "bJtDzXMnS1ufL1SHarZnMA",
"file_name": "test.txt",
"file_size": 28
}
],
"delete_file_id_list": ["-i81TZFYSK2KUltQP-Y_TA"]
}
}
```
| Field | Type | Description |
| --------------------- | ---------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | Chat data sent from the media connection. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `timestamp` | unsigned long | The Unix timestamp of the data. |
| `data` | string | The message content. A UTF-8 encoded JSON object string. |
| `chat_session` | object | The chat session that the message belongs to. |
| `chat_session.type` | int | The type of chat session. RTMS currently only delivers `1` (`EVERYONE`, public chat). For more information, see [RTMS_CHAT_SESSION_TYPE](/docs/rtms/data-types/#rtms_chat_session_type). |
| `operation_type` | int | The operation that produced this message, such as send, edit, or delete. For more information, see [RTMS_CHAT_OPERATION_TYPE](/docs/rtms/data-types/#rtms_chat_operation_type). |
| `message_id` | string | The unique identifier of the message. |
| `sender` | object | The participant who sent the message. |
| `sender.user_id` | unsigned int32 | The unique identifier of the participant who sent the message. |
| `sender.user_name` | string | The username of the participant who sent the message. |
| `files` | array | The files attached to the message. |
| `files[].file_id` | string | The unique identifier of the attached file. |
| `files[].file_name` | string | The name of the attached file. |
| `files[].file_size` | unsigned long | The size of the attached file, in bytes. |
| `delete_file_id_list` | array | Optional. The identifiers of files removed while editing a chat message. Only present when files are removed during an edit. |
## Session state updated
Sent from the signaling connection
The signaling connection sends session state updated events when a new session is added or the state of a session is changed. A session can stop and resume during a stream. This message does not require a response from the app.
The `STARTED` state means a brand-new session has started. Record the session information locally since the state of each session is changed separately.
```json
{
"msg_type": 9,
"state": 1,
"stop_reason": 1,
"timestamp": 1727384349123,
"rtms_session_id": "xxxxxxxxxx"
}
```
| Field | Type | Description |
| ----------------- | --------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `msg_type` | int | The signaling connection sends this message when a session has been updated. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `state` | int | The state of a session within a stream, including if a participant or host has started, paused, resumed or stopped a session. For more information, see [RTMS_SESSION_STATE](/docs/rtms/data-types/#rtms_session_state). |
| `reason` | int | Describes why a session status has been updated. It's only sent if session state stops. For more information, see [RTMS_STOP_REASON](/docs/rtms/data-types/#rtms_stop_reason). |
| `timestamp` | unsigned long | The Unix timestamp of when the session was updated. |
| `rtms_session_id` | string | The unique identifier for the RTMS session. |
## Session state request
Sent to the signaling connection
Apps send the session state request event to the signaling connection to query the current session state. The signaling connection will respond with the current session state.
```json
{
"msg_type": 10,
"rtms_session_id": "xxxxxxxxxx"
}
```
| Field | Type | Description |
| ----------------- | --------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The app sends this message to query the current state of the session. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_session_id` | string | The unique identifier for the RTMS session. |
## Session state response
Sent from the signaling connection
The signaling connection sends the session state response event in response to a session state request event.
```json
{
"msg_type": 11,
"rtms_session_id": "xxxxxxxxxx",
"state": 1,
"timestamp": 1727384349123
}
```
| Field | Type | Description |
| ----------------- | --------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The signaling connection sends this field as a response to the query for the state of the current session. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_session_id` | string | The unique identifier for the RTMS session. |
| `state` | int | The state of the current session. For more information, see [RTMS_SESSION_STATE](/docs/rtms/data-types/#rtms_session_state). |
| `timestamp` | unsigned long | The Unix timestamp of the request. Use this to pair requests and responses. |
## Stream state request
Sent to the signaling connection
Apps send the current stream state request event to the signaling server to query the current stream state. Streams can be in one of the following states: inactive, active, interrupted, terminating, terminated, paused, or resumed.
```json
{
"msg_type": 19,
"rtms_stream_id": "756FF58A-6332-6ECA-E4AE-21F2ABDCB485"
}
```
| Field | Type | Description |
| ---------------- | --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `msg_type` | int | The app sends this message to query the current state of the state. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_stream_id` | string | The unique identifier of the RTMS stream. |
## Stream state response
Sent from the signaling connection
The signaling connection sends the stream state response event in response to a stream state request event.
```json
{
"msg_type": 20,
"state": 1,
"rtms_stream_id": "756FF58A-6332-6ECA-E4AE-21F2ABDCB485",
"timestamp": 1694204592
}
```
| Field | Type | Description |
| ---------------- | --------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The signaling connection sends this message as a response to the query for the state of the current stream. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `state` | int | The current state of the RTMS stream. For more information, see [RTMS_STREAM_STATE](/docs/rtms/data-types/#rtms_stream_state). |
| `rtms_stream_id` | string | The unique identifier for the RTMS stream. |
| `timestamp` | unsigned long | The Unix timestamp of the request. Use this to pair requests and responses. |
## Stream state updated
Sent from the signaling connection
```json
{
"msg_type": 8,
"state": 1,
"reason": 1,
"timestamp": 1727384349123
}
```
| Field | Type | Description |
| ----------- | --------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The signaling connection sends this message when a stream has been updated. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `state` | int | The state of a stream, including if a stream is active, experiencing connection issues, or needs to be terminated. For more information, see [RTMS_STREAM_STATE](/docs/rtms/data-types/#rtms_stream_state). |
| `reason` | int | Describes why a stream status has been updated. For more information, see [RTMS_STOP_REASON](/docs/rtms/data-types/#rtms_stop_reason). |
| `timestamp` | unsigned long | The Unix timestamp of when the stream was updated. |
## Stream close request
Sent to the signaling connection
To gracefully close a stream from the app backend, send a `STREAM_CLOSE_REQ` message through the signaling connection. RTMS will respond with a `STREAM_CLOSE_RESP` message and terminate the stream.
```json
{
"msg_type": 21,
"rtms_stream_id": "xxxxxxxxxx"
}
```
| Field | Type | Description |
| ---------------- | --------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The request from the app to close the stream. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_stream_id` | string | The unique identifier of the RTMS stream to close. |
## Stream close response
Sent from the signaling connection
The signaling connection responds to a stream close request with a `STREAM_CLOSE_RESP` message confirming the result.
```json
{
"msg_type": 22,
"rtms_stream_id": "xxxxxxxxxx",
"status_code": 0,
"reason": "OK",
"timestamp": 1727384349123
}
```
| Field | Type | Description |
| ---------------- | --------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The response from the signaling connection after a stream close request. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `rtms_stream_id` | string | The unique identifier of the RTMS stream. |
| `status_code` | int | The status code of the response. Status `0` means success. For more information, see [RTMS_STATUS_CODE](/docs/rtms/data-types/#rtms_status_code). |
| `reason` | string | Empty if successful. If failed, contains the reason for the failure. |
| `timestamp` | unsigned long | The Unix timestamp of when the response was sent. |
## Video subscription request
Sent to the signaling connection
To use individual video subscriptions, configure `data_opt` to `4` (`VIDEO_SINGLE_INDIVIDUAL_STREAM`) when establishing the media connection, and subscribe to `PARTICIPANT_VIDEO_ON` and `PARTICIPANT_VIDEO_OFF` events using the [Subscribe to events](#subscribe-to-events) message.
To subscribe to an individual participant's video stream, send this message through the signaling connection containing the `user_id` obtained from a `PARTICIPANT_VIDEO_ON` event. The RTMS server supports subscribing to a single individual video stream at a time, a new subscription request will automatically unsubscribe from the previous individual's stream.
```json
{
"msg_type": 28,
"user_id": 16778240,
"subscribe": true,
"timestamp": 1738392033699
}
```
| Field | Type | Description |
| ----------- | ---------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The request from the app to subscribe or unsubscribe from an individual's video stream. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | unsigned int32 | The unique identifier of the participant to subscribe to, obtained from a `PARTICIPANT_VIDEO_ON` event. |
| `subscribe` | bool | Set to `true` to subscribe, `false` to unsubscribe. |
| `timestamp` | unsigned long | The Unix timestamp of the request. |
## Video subscription response
Sent from the signaling connection
The signaling connection responds to a video subscription request. If successful, the subscribed participant's video stream will begin transmitting through the video data socket connection.
```json
{
"msg_type": 29,
"user_id": 16778240,
"status_code": 0,
"reason": "OK",
"timestamp": 1738392033699
}
```
| Field | Type | Description |
| ------------- | ---------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `msg_type` | int | The response from the signaling connection after a video subscription request. For more information, see [RTMS_MESSAGE_TYPE](/docs/rtms/data-types/#rtms_message_type). |
| `user_id` | unsigned int32 | The unique identifier of the participant that was subscribed or unsubscribed. |
| `status_code` | int | The status code of the response. Status `0` means success. For more information, see [RTMS_STATUS_CODE](/docs/rtms/data-types/#rtms_status_code). |
| `reason` | string | Empty if successful. If failed, contains the reason for the failure. |
| `timestamp` | unsigned long | The Unix timestamp of the response. |